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Our Price: $299.95

Description  more details

Click here to download installation instructions (PDF)

RELEASED 9.11.23
The Fuel Pressure Regulator Damper-Rotating Assembly (FPRD-RA) is the ultimate solution for consolidating critical fuel system components into a high-flow package. It is a fully functional high performance pressure regulator with a unique built-in fuel pulse damper.

This regulator features two M6x1mm threaded mounting holes. A laser cut anodized aluminum mounting plate is provided with 4 countersink M6x1mm bolts/nuts.

The FPRD-RA can be mounted any direction including upside down.

The inlet (side) and outlet (bottom) feature large 10AN ORB (7/8"-14) threaded ports. Two -6AN and two -8AN male adapter fittings are included to suit most aftermarket fuel systems. When installing ORB fittings, first lubricate the O-rings with petroleum oil. 
The 1/8" NPT auxilary port can be used for monitoring fuel pressure, temperature, etc. The Radium fuel pressure gauge is commonly used. An included preimpregnated PTFE plug can be used if this port is not needed. When installing a different NPT fitting, PTFE paste is required for proper sealing.

NOTE: This regulator has a single inlet port and single outlet (return) port. Because of this, it cannot be used in a dead-head fuel system. It must be plumbed AFTER the fuel rail.  Check out the Multi-Port Regulator (MPR) for dead-head fuel plumbing. 

The integrated 1:1 fuel pulse damper stabilizes fuel pressure created by the fuel pump, fuel injectors, regulator, etc. The base pressure requirement for maximum damping efficiency is 40-105psi (2.8-7.2bar). This range is base static pressure only. For dynamic fuel pressue outside this range, the vacuum/boost reference line will be required.  

1. Base pressure is measured with the fuel pump running without a vacuum line connected to the regulator.
2. This product is NOT FOR USE on the low pressure side of mechanical fuel pumps.

RA-series regulators feature the first tool-less pressure adjustment. A jam nut and set screw are no longer required. With a simple turn of the knob, pressure will be increased or decreased. 

To aid in adjusting pressure, there are incremental detents that provide haptic feedback to the user. Every detent permits 1psi (+/-0.5psi) of adjustment depending on current fuel pressure.
With years of track and bench testing data, the RA-series regulators have been refined to optimize pressure management. A newly designed single stainless steel return orifice generates laminar flow that enhances stability control.

Minimum Pressure: 18.5psi (1.3bar)
Maximum Pressure: *N/A
*This is rhetorical. The maximum pressure is dependent on the relief valve inside the pump or the maximum current the fuel pump controller allows. 
RA-series regulators feature a 360 degree swiveling vacuum reference port that is double O-ring sealed. This is the first in the industry. It permits the installer to quickly point the vacuum fitting in any direction with no tools required.

There are 4 interchangeable 10-32 threaded vacuum port fittings provided to cover all scenarios. 

1. Barbed Fitting: A black zinc-plated 3/16" (5mm) barb machined from high strength steel that is compatible with the following vacuum hoses: 5/32" (4mm), 3/16" (5mm), and 7/32" (6mm).
2. 3AN Male Fitting: A black zinc-plated adapter machined from high strength steel that is compatible with 3AN hose ends.
3. Push-To-Connect: A nickel-plated brass fitting with Buna-N O-rings that is compatible with hard plastic 1/4" OD tubing.
4. Vacuum Plug: A black oxide stainless steel screw that is used to maintain a constant (non dynamic) fuel pressure. Beginning in the mid 1990s, vehicle manufacturers started transitioning to returnless fuel systems to lower EVAP emissions. To keep temperatures lower, these regulators are mounted inside the tank and do NOT have the ability to be vacuum referenced. This plug would be required in this scenario.

NOTE: When installing the vacuum fitting, it is recommended to use a wicking medium-strength threadlocker.

All RA-series regulators are suitable with all gasoline types including unleaded, leaded, oxygenated, and pre-mixes. Furthermore, they are compatible with alcohol blends of fuel including methanol, ethanol, and E85. 

-Main Rotating Assembly with Damper
-Mounting Bracket with M6x1mm Hardware
-5mm Barbed Vacuum Fitting (x2)
-Vacuum Plug Fitting, Returnless (x2)
-1/4" Push-To-Connect Fitting (x2)
-3AN Male Vacuum Fitting (x2)
-6AN male Adapter (x2)
-8AN male Adapter (x2)
-1/8" NPT Port Plug
-Vacuum Hose Y-adapter
-Vacuum Hose, 5/32" ID


Adding a fuel pressure gauge makes pressure adjustments simple.

After applying PTFE paste to the threads, the gauge will seal into the 1/8" NPT port on the regulator. For more information on the fuel pressure gauge, click HERE.
The graph below shows the minimum fuel pressure the regulator can achieve as a function of pump flow rate. For example, if you have two pumps that flow 320LPH (total 640LPH), the approximate minimum pressure the regulator can achieve is about 30psi. If an OEM fuel pressure regulator sees 640LPH for instance, it will likely not be able to bypass enough fuel.

NOTE: This test was performed with the adjustment knob completely backed out, no preload.